NOTES ON CERTAIN PARASITIC PROTOZOA 23. 



with some diseases of man, other mammals, and birds, are bacteria 

 or protozoa. Amongst them is the Spirillum Obermeieri of human 

 relapsing fever. Recent observations appear to suggest that this 

 organism depends upon the common bed-bug for its transference. 

 The parasite of African relapsing fever (or tick-fever) has been found 

 by R. Koch 1 and others to depend for its transference upon a tick. 

 Ornithodorus moubata, in which the spirochaetse pass through two 

 generations, the infection being given by larval ticks born of parents 

 that originally fed upon infected blood. Koch found great numbers 



3 



FIG. 6. SPIROCH/ETA AND SPIRONEMA. (After Schaudinn, from Dcutsch. Meet- 



Woch., October 19, 1905.) 



i, Spirochata refringens, a common spirochaete ; 2, Spironema of syphilis ; 

 3, Spironema of syphilis (?) dividing. 



of spirochsetse in the ovaries of ticks, but he did not detect the 

 developmental stages described by Schaudinn in Sp. Ziemanni. 

 The spirilloses of birds are conveyed by ticks belonging to the 

 Argasidcz (see Chapter V.). The spiral organism (Fig. 6) discovered 

 in syphilis, and named Spiroch&ta pallida by Schaudinn, differs from 

 a typical spirochaeta such as Sp. refringens (Fig. 6) in having slender 

 flagellum-like extremities, and on this account its name was subse- 

 quently changed to Spironema luis. Whether this organism has 

 other developmental stages will be discussed below. Two American 

 observers, Novy and McNeil, regard the organism of tick-fever as a 

 protozoon, and name it Spirochceta Duttoni ; the Spirillum Obermeieri^ 

 1 R. Koch, Deutsch. Med. Woch., 1905, No. 47 (quoted by Minchin he. supra /.) 



